Franz muller



(No Model.)

P. MULLER.

PENDENT MIGROTELEPHONE.

No. 586,689 Patented July 20, 189? face/yer iwa ewiar f4ca' we NORRIS Pnzas co, norourno wAsHmswm-o c UNiTnn STATES PATENT OFFICE.

FRANZ MiLLER, or BERLIN, GERMANY.

PENDENT MICROTELEPHONE.

SPECIFICATION forming part of Letters Patent No. 586,689, dated July 20, 1897. Application filed December 12, 1896. Serial No. 615,479. (No model.)

To all Ir/mnt if /;1.// concern- Be it known that I, FRANZ MULLER, a subject of the King of Prussia, German Emperor, and a resident of Berlin, in the Kingdom of Prussia, German Empire, have invented certain new and useful Improvements in Pendent Microtelephones, of which the following is an exact specification.

This invention refers to microtelephones of the kind in which the microtelephone is held by means of a cord containing the conducting-wires and is suspended from a suitable bracket or other support arranged at or near to the plate (desk, dining-table, or the like) of the person for the use of whom the microtelephone is intended.

My improvements in microtelephones of said kind relate to the automatic switch employed with the same; and my improvements consist in letting the switch be operated in one direction by a spring having a strength greater than the weight of the fixed or stationary part of the apparatus containing the microphone and in the other direction by the part of the apparatus containing the telephone, or, more precisely, by the weight of said last-mentioned part, said weight being so great as to be able to overcome the strength of the spring aforementioned if it is combined or coacts with the weight of the part containing the microphone.

In the prior constructions known to me the automatic switch is operated by putting the two parts together-i. 6., by shoving one part into the other. If the person using the apparatus, and separating and reuniting, therefore, the microphone and the telephone, does not eiitect said reuniting with proper care the contact established is bad and the apparatus does not work as good as desired. In many cases the apparatus does not work at all that is to say, a signal calling the person to its apparatus cannot be given.

The object of my improvements therefore is to make the apparatus independent of the care of the operator, and I attain that object by the means that have been mentioned in preceding paragraph.

In order to make my invention more clear, I refer to the accompanying drawings, in which similar letters denote similar parts throughout both views, and in which- Figure 1 is a side view of my improved microtelephone, the two parts being put together. Fig. 2 shows the two parts discon nected, the upper part being partly in section.

The upper part A contains the microphone, the lower part B the telephone. I have thought it unnecessary to represent the details of the microphone and the telephone because said details are known and are not in direct connection with the subjectmatter of my invention. The circuit including the microphonet'. e, the circuit that is to be closed on the part B being taken off the part A-contains the contact-pieces c c, which are held by the insulating-pieces (Z d. Said contact-pieces c care put into conductive connection by the pin 6 when the part B is removed from the part A. The upper portion of the latter is provided with a hollow knob f, through which passes the pin aforementioned. The pin a is encompassed by a spring g, which presses at its upper end against the closed top portion of the knobfand at its lower end against a small pin It, passed in crosswise direction through the lower end of the pin c. The up per end of the latter is provided with an ear 2', that serves for connecting the apparatus to the suspending-cord it. The branches 70 k of this cord lead the conducting-wires. to and into the interior of the microphone A. The wires connecting the microphone with the telephone B are contained within the cord 7.3

Having thus fully described the nature of this invention, what I desire to secure by Letters Patent of the United States is 1. In a pendent microtelephone consisting of two separable parts containing one the microphone and the other the telephone, and having one of said parts arranged below, and held by, the other, the combination with the upper part, of an automatic switch interposed between said part and the means for holding the whole microtelephone; and being adapted to be operated in one direction by a spring having a strength adapted to overcome the weight of said upper part, and in the other direction by the combined weights of the said upper and said lower part, for the purpose as described.

2. In a pendent microtelephone consisting of two separable parts containing one the microphone and the other the telephone, and

having one of said parts arranged below, and held by, the other, the combination with the upper part, of two stationary contact-pieces arranged Within the latter, and insulated one from the other, and a movable contact-piece adapted to put said other pieces into, and throw them out of, contact; said movable contact-piece being interposed between said up per part and the means for holding the whole microtelephone, and being adapted to be operated in one direction by a spring having a strength adapted to overcome the weight of said upper part, and in the other direction by the combined weights of the said upper and said lower part, for the purpose as described. In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

FRANZ MULLER. \Vitnesses:

RICHARD ARONS, LUDWIG PFEIFFER. 

